droid

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By now we’ve come to expect a bountiful harvest of licensed merchandise to follow every Star Wars film. This year’s crop included many flavors of BB-8 so every fan can find something to suit their taste. At the top of this food chain is a mobile interactive “Hero Droid BB-8”. For those who want to see how it works, [TheMikeSenna] cracked open his unit to feed our curiosity.

Also called “Spin Master BB-8” for the manufacturer, this toy is impressively sophisticated for its price point. The video surveyed the mechanical components inside the ball. Showing how the droid travels, and how the head articulates.

The ‘Gonk’ droids from the Star Wars universe are easy to overlook, but serve the important function of mobile power generators. Here on Earth, [bithead942]’s life-size replica droid fulfills much the same purpose.

Cronk — functionally an oversized USB charging hub with a lot of bells and whistles — is remotely controlled by a modified Wii Nunchuck very controller similar to the one [bithead942] used to control his R2-D2. With the help of an Adafruit Audio FX Mini, an Adafruit Class D 20W amp, and two four-inch speakers, the droid can rattle off some sound effects as it blows off some steam(really, an inverted CO2 duster). An Arduino Mega acts as Cronk’s brain while its body is sculpted from cast-able urethane foam for its light weight and rigidity. It also houses a FPV camera, mic, and DVR so it can be operated effectively from afar.

We’ve been following [James Bruton]’s builds here on Hackaday for quite a while and he has built some impressive stuff. We love how he often doesn’t cover everything up, leaving enough room to admire the working bits under the hood. Just in time for the release of the new Star Wars movie, Rogue One, [James] put together an overview of his Star Wars robot builds.

The build summary includes his R6 droid, his GNK walking droid and the third revision of his BB-8 droid. [James Bruton]’s videos have tons of detail in them over many, many parts (for example, his BB-8 R3 playlist is 15 parts and his Ultron build currently has 26 episodes and counting!)

There’s a quick overview of each of the three robot builds in this video, and it includes links to the playlists for each build for those who want more detail. This is just what you need to glimpse all of the clever design that went into these wonderfully crafted droids. And if you haven’t seen it yet, you should check out his series elastic actuators that he’s working on for the Ultron build, they give a robot some relief from rigidity.

Finally the workings of the official BB-8 that you’ve seen rolling around at various events have been revealed. Its makers [Matt Denton] and [Josh Lee] participated in an hour-long presentation at Star Wars Celebration Europe 2016 just this past week where the various views of its internals were shown in action. It’s since had BB-8 builders (yours truly included) analyzing the workings for new ideas. We also now have the official name for it, red carpet BB-8.

For the first half of their talk they went over how BB-8 was implemented for Star Wars: The Force Awakens. As we’ve long known this was done using 7 puppeted BB-8’s, though it was revealed that only 4 were actually used, including a stationary one called the wiggler whose purpose you can guess. Another thing we didn’t know is that they did consider building a working BB-8 for filming but decided they needed something bullet proof, that would work right every time without making a film crew wait for repairs, and so went with the puppets instead.

The second half of their talk contained the big reveal, the mechanism inside red carpet BB-8’s ball. It turns out to be pretty close to what many builders have been doing. If you’ve seen the DIYer’s guide to the different BB-8 drive systems then you’ll understand when we say it’s a pendulum drive (aka axle drive). That is, there’s a motorized axle that crosses the middle of the ball and the ball rotates on that axle. Meanwhile a large mass suspended below the axle acts as the pendulum mass.

Red Carpet BB-8 side with cables

Red Carpet BB-8 side with actuator

BB-8 builders have known the importance of keeping as much mass as possible as low down as possible for stability, but it was revealed the great extent to which that has been done in the red carpet version. Motors for the head’s pitch and yaw are located at the bottom and their motion is transferred up to the center using what are maybe best known as bicycle brake cables. Another big reveal was a linear actuator for the body roll, tilting the center stuff with respect to the mass lower down. The actuator itself is located in the lower section. Also, BB-8 builders have been mounting the drive motors for rotating the ball with respect to the axle, in line with the axle. However, in red carpet BB-8 the motor is also at the bottom and its motion appears to be transferred up to the axle via belt and worm gears. You may mistake the gold cylinders on either side of the central gimbal system to be motors but they’re actually Moflon slip rings.

Those are just a few of the insights gained so far from analyzing the video below. Doubtless people will be noticing a lot more in the weeks to come.

BB-8 is the much loved new droid introduced in the 2016 movie Star Wars: The Force Awakens, though in my case from the very first trailer released in 2014 I liked it for the interesting engineering problems it posed. How would you make a robot that’s a ball that rolls along, but with a head that stays on top while the ball rolls under it?

BB-8 in 1st Star Wars: The Force Awakens trailer

Hamster in hamster wheel

To make the ball roll, the answer most people found obvious at first was to use the analogy of a hamster wheel. The hamster running inside makes the wheel turn. In the BB-8 building world, which is quite large, the drive mechanism has come to be called a hamster drive, or just a hamster.

Magnets holding the head on

For the head, it seemed obvious that there would be magnets inside the ball, perhaps held in place near the top of the ball by a post extending up from the hamster. Corresponding magnets in attraction would then be attached to the underside of the head, and balls (also mounted under the head) would keep the head moving smoothly over the ball.

The magnet approach for the head has turned out to be the method used by all BB-8 builders that I’ve seen. However, the hamster has turned out to be only one of multiple solutions. Since the original debut many different methods have been used in builds and we’re going to have a lot of fun looking at each separate approach. It’s almost like revealing a magic trick; but really it’s all just clever engineering.

Note that for the actual movie, a combination of 7 or 8 props and CGI were used. The official working BB-8s that are shown at various promotional events were built after the movie was made and as of this writing, few details of their construction have been released. One notable detail, however, is that they aren’t using hamster drives.

Below are details of all the different BB-8 drive systems I’ve seen so far that have been built along with how they work.

Star Wars is an inspirational force to be reckoned with. Few movie franchises have quite so many fans creating everything from elaborate cosplay outfits to fully functional robots. At the 2015 Hackaday SuperCon, former R2D2 driver Grant Imahara mentioned that LucasArts used to maintain a fleet of robots to be deployed at events. Once the execs realized hacker, maker, and hobbyist robots are now more advanced than the machines they built for the actual films, they mothballed the fleet. If you see R2 at a Star Wars event this season, it’s probably an enthusiast behind the controls. This week’s Hacklet is dedicated to the best Star Wars projects on Hackaday.io!

We start with [Nathan Gray] and Star Wars Nerf Targets. [Nathan] needed a Star Wars themed game for an event for the kids, and he needed it fast. [Nathan] built a Nerf shooting gallery game with a Star Wars twist. The idea is to shoot the bad guys with Nerf darts. Targets have two sides, so you never can be sure if you’ll see a storm trooper or a friendly Wookie. Hits are detected by piezoelectric disks on each target. A control panel starts the game, keeps score, and plays some great sound effects. An Arduino compatible Teensy 2.0 keeps everything running smoothly. [Nathan] reports that the game was a hit with the kids, and everyone else at the party. Even Grandma had to give the Star Wars Nerf Targets game a try!

Next up is Hackaday’s own [Brian Benchoff] with The Hackaday Prize Moisture Vaporator. The 2015 Hackaday Prize promo video called for something space related. Since Southern California has plenty of desert around, a moisture vaporator straight out of Tatooine was just what the doctor ordered. [Brian], [Matt], [Rich] and [Alek] handled most of the construction at the Hackaday Hackerspace in Pasadena. Final assembly was a team effort out in the field. The basic frame of the vaporator consisted of 1 x 3 lumber joined with pocket screws. An iron pipe served as the spine. [Brian] added plenty of greebles to give the vaporator just the right look. The result makes us long for a trip to Toshi Station to pick up some power converters.

[Davedarko] is up next with Towani Lifesign Wristdevice – Star Wars Ewoks. This was one of [Dave’s] earliest projects on Hackday.io, way down at project #616. He originally built it for the Sci-Fi contest we held in 2014. The Towani family was in the Ewoks movies, which were lesser known spinoffs of the original Star Wars films. The wristbands showing the family’s vitals were featured a few times in the movies. [Dave’s] version is more than a movie prop, it actually works. He’s using an open hardware pulse sensor along with an Arduino Mini to display status on a trio of LEDs.

Finally, we have [Enrico] with Our own BB-8 droid. BB-8 made a splash when he rolled out on stage during Star Wars Celebration. Everyone wondered how the original was done. We’ve since found out that the BB-8 uses Sphero’s technology to get around. However, many of the movie scenes were done with good old-fashioned puppeteer work. [Enrico] is building his own version of BB-8 using holonomic wheels inside the sphere, with a magnetically attached head. He’s planning to 3D print the major parts of his droid. So far, [Enrico] has started testing with magnets. A few printed plastic parts from his R2D2 build have been standing in for the BB-8 shell.

If you want to see more Star Wars projects, check out our new Star Wars project list! If I missed your project due to a great disturbance in the force, don’t be a nerf herder! Just drop me a message on Hackaday.io. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io! May the force be with you.

BB-8 the new droid in the star wars franchise made his first public appearance (YouTube link) at Star Wars Celebration last week. While cast and crew of the movie have long said that BB-8 is real, seeing it up on stage, driving circles around R2D2 takes things to a whole new level. The question remains, how exactly does it work?

Our (and probably any other tech geek worth their salt’s) immediate reaction was to think of xkcd’s “New Pet” comic. All the way back in 2008, [Randall Munroe] suggested omnidirectional wheels and magnets could be used to create exactly this kind of ‘bot. Is this what’s going on inside BB-8? No one knows for sure, but that won’t stop us from trying to figure it out!

The Head

So if BB-8’s body is based on a Sphero, how does the head work? The Disney crew has been mum on this so far, but there is plenty of speculation! If you watch the video in HD, several flashes can be seen between the body and head gap. These might be status LEDs on BB-8’s electronics, but they could also be IR LEDs – possibly part of an optical mouse style sensor. Sensor fusion between gyroscopes, accelerometers and the optical flow sensors would make for a robust solution to the inverted pendulum problem presented by BB-8’s head.

How do you think BB-8 works? Is it magnets, motors, or The Force? Let us know in the comments!